Thoracic outlet syndrome is a group of disorders that occur when the blood vessels or nerves in the space between your collarbone and your first rib (thoracic outlet) become compressed. This can cause pain in your shoulders and neck and numbness in your fingers.

Common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive injuries from job- or sports-related activities, certain anatomical defects (such as having an extra rib), and pregnancy. Sometimes doctors can't determine the cause of thoracic outlet syndrome.

Treatment for thoracic outlet syndrome usually involves physical therapy and pain relief measures. Most people improve with these approaches. In some cases, however, your doctor may recommend surgery.

Generally, there are three types of thoracic outlet syndrome.

Neurogenic (neurological) thoracic outlet syndrome. This form of thoracic outlet syndrome is characterized by compression of the brachial plexus. The brachial plexus is a network of nerves that come from your spinal cord and control muscle movements and sensation in your shoulder, arm and hand.

In the majority of thoracic outlet syndrome cases, the symptoms are neurogenic.

Vascular thoracic outlet syndrome. This type of thoracic outlet syndrome occurs when one or more of the veins (venous thoracic outlet syndrome) or arteries (arterial thoracic outlet syndrome) under the collarbone (clavicle) are compressed.

Nonspecific-type thoracic outlet syndrome. This type is also called disputed thoracic outlet syndrome. Some doctors don't believe it exists, while others say it's a common disorder.

People with nonspecific-type thoracic outlet syndrome have chronic pain in the area of the thoracic outlet that worsens with activity, but the specific cause of the pain can't be determined.

Thoracic outlet syndrome symptoms can vary, depending on which structures are compressed. When nerves are compressed, signs and symptoms of neurological thoracic outlet syndrome include:

Wasting in the fleshy base of your thumb (Gilliatt-Sumner hand)

Numbness or tingling in your arm or fingers

Pain or aches in your neck, shoulder or hand

Weakening grip

Signs and symptoms of vascular thoracic outlet syndrome can include:

Discoloration of your hand (bluish color)

Arm pain and swelling, possibly due to blood clots

Blood clot in veins or arteries in the upper area of your body

Lack of color (pallor) in one or more of your fingers or your entire hand

Weak or no pulse in the affected arm

Cold fingers, hands or arms

Arm fatigue after activity

Numbness or tingling in your fingers

Weakness of arm or neck

Throbbing lump near your collarbone

When to see a doctor

See your doctor if you consistently experience any of the signs and symptoms of thoracic outlet syndrome.

In general, the cause of thoracic outlet syndrome is compression of the nerves or blood vessels in the thoracic outlet, just under your collarbone (clavicle). The cause of the compression varies and can include:

Anatomical defects. Inherited defects that are present at birth (congenital) may include an extra rib located above the first rib (cervical rib) or an abnormally tight fibrous band connecting your spine to your rib.

Poor posture. Drooping your shoulders or holding your head in a forward position can cause compression in the thoracic outlet area.

Trauma. A traumatic event, such as a car accident, can cause internal changes that then compress the nerves in the thoracic outlet. The onset of symptoms related to a traumatic accident often is delayed.

Repetitive activity. Doing the same thing repeatedly can, over time, wear on your body's tissue.

You may notice symptoms of thoracic outlet syndrome if your job requires you to repeat a movement continuously, such as typing on a computer, working on an assembly line or lifting things above your head, as you would if you were stocking shelves.

Athletes, such as baseball pitchers and swimmers, also can develop thoracic outlet syndrome from years of repetitive movements.

Pressure on your joints. Obesity can put an undue amount of stress on your joints, as can carrying around an oversized bag or backpack.

Pregnancy. Because joints loosen during pregnancy, signs of thoracic outlet syndrome may first appear while you're pregnant.

If you haven't been treated early in the condition, soon after you noticed symptoms, then you may experience progressive nerve damage, and you may require surgery.

Doctors recommend surgery to treat thoracic outlet syndrome only when other treatments haven't been effective. Surgery has higher risks than do other treatments and may not always treat your symptoms.

You're likely to start by seeing your family doctor or a general practitioner. In some cases, your doctor may refer you to a doctor trained in blood vessel (vascular) conditions or blood vessel surgery.

Here's some information to help you prepare for your appointment.

What you can do

Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do before you arrive at the office.

Write down any symptoms you're experiencing, including any that seem unrelated to the reason for which you scheduled the appointment. Be as specific and detailed as possible in describing your symptoms, including what part of your body is affected and what adjectives describe your discomfort.

Write down key personal information, including any physical traumas such as a car accident or work-related injury. Even if they occurred years ago, your doctor will want to know about them.

Also note any repetitive physical activities that you've performed now or in the past at work, in sports, and for hobbies and other recreational activities.

List your key medical information, including other conditions you're being treated for and the names of any prescription and over-the-counter medications or supplements that you're taking.

Take a family member or friend along, if possible. Someone who accompanies you may remember something that you missed or forgot.

Write down questions to ask your doctor.

Preparing a list of questions will help you make the most of your time with your doctor. For thoracic outlet syndrome, some basic questions to ask your doctor include:

What is likely causing my symptoms or condition?

Are there any other possible causes for my symptoms or condition?

What kinds of tests do I need?

What treatment approach do you recommend?

How likely are nonsurgical treatments to improve my symptoms?

If conservative treatments aren't effective, is surgery an option?

Is there anything I can do to prevent a recurrence of this problem?

Will I need to change my job?

Do I need to limit or give up other activities that may be causing my symptoms?

If you're recommending weight loss, how much weight do I need to lose to notice an improvement in my symptoms?

I have other health conditions. How can I best manage them with this condition?

Should I see a specialist?

Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

Don't hesitate to ask any other questions you have.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, such as:

When did you begin experiencing symptoms?

How would you describe your symptoms?

Have your symptoms changed over time?

Where does your pain seem to start and where does it go from there?

Does the pain or numbness worsen when you lift your arms overhead?

Does anything else seem to worsen or improve your symptoms?

What activities do you perform on your job?

Do you or did you play sports?

What are your hobbies or most frequent recreational activities?

Have you been diagnosed or treated for any other medical conditions? When?

Have you noticed a lack of color or a blue color in one or more of your fingers or your entire hand or other changes to the area?

What you can do in the meantime

Your discomfort also may be improved if you maintain good posture and avoid using repetitive movements and lifting heavy objects.

Diagnosing thoracic outlet syndrome can be difficult because the symptoms and their severity can vary greatly among people with the disorder. To diagnose thoracic outlet syndrome, your doctor may review your symptoms and medical history and conduct a physical examination.

Physical examination. Your doctor will perform a physical examination to look for external signs of thoracic outlet syndrome, such as a depression in your shoulder, swelling or pale discoloration in your arm, abnormal pulses, or limited range of motion.

Medical history. Your doctor will likely ask about your medical history and symptoms, as well as your occupation and physical activities.

Provocation tests

Provocation tests are designed to reproduce your symptoms. The tests may help your doctor determine the cause of your condition and help rule out other causes that may have similar symptoms.

In these tests, your doctor may ask you to move your arms, neck or shoulders in various positions. Your doctor will assess your symptoms and examine you in different positions.

Imaging and nerve study tests

To confirm the diagnosis of thoracic outlet syndrome, your doctor may order one or more of the following tests:

X-ray. Your doctor may order an X-ray of the affected area, which may reveal an extra rib (cervical rib). X-rays also may rule out other conditions that may be causing your symptoms.

Ultrasound. An ultrasound uses sound waves to create images of your body. Doctors may use this test to see if you have vascular thoracic outlet syndrome or other vascular problems.

Computerized tomography (CT) scan. A CT scan uses X-rays to obtain cross-sectional images of your body. A dye may be injected into a vein to view the blood vessels in greater detail (CT angiography).

A CT scan may identify the location and cause of blood vessel (vascular) compression.

Magnetic resonance imaging (MRI). An MRI uses powerful radio waves and magnets to create a detailed view of your body.

Your doctor may use an MRI to determine the location and cause of blood vessel (vascular) compression. An MRI may reveal congenital anomalies, such as a fibrous band connecting your spine to your rib or a cervical rib, which may be the cause of your symptoms.

Doctors don't often use this test to diagnose thoracic outlet syndrome. However, imaging tests may rule out other conditions that may be causing your symptoms, such as spine or brain conditions.

Arteriography and venography. In these tests, your doctor inserts a thin, flexible tube (catheter) through a small incision, usually in your groin. The catheter is moved through your major arteries in arteriography, or through your veins in venography, to the affected blood vessels. Then your doctor injects a dye through the catheter to show X-ray images of your arteries or veins.

Doctors can check to see if you have a compressed vein or artery. If a vein or artery has a clot, doctors can deliver medications through the catheter to dissolve the clot.

Electromyography (EMG). During an EMG, your doctor inserts a needle electrode through your skin into various muscles. The test evaluates the electrical activity of your muscles when they contract and when they're at rest.

Nerve conduction study. These tests use a low amount of electrical current to test and measure your nerves' ability to send impulses to muscles in different areas of your body. This test can determine if you have nerve damage.

In most cases, a conservative approach to treatment is effective, especially if your condition is diagnosed early. Treatment may include:

Physical therapy. If you have neurogenic thoracic outlet syndrome, physical therapy is the first line of treatment. You'll learn how to do exercises that strengthen and stretch your shoulder muscles to open the thoracic outlet, improve your range of motion and improve your posture.

These exercises, done over time, may take the pressure off your blood vessels and nerves in the thoracic outlet.

Clot-dissolving medications. If you have venous or arterial thoracic outlet syndrome and have blood clots, your doctor may administer clot-dissolving medications (thrombolytics) into your veins or arteries to dissolve blood clots. After you're given thrombolytics, your doctor may prescribe medications to prevent blood clots (anticoagulants).

Surgical options

Your doctor may recommend surgery if other treatment hasn't been effective, if you're experiencing ongoing symptoms or if you have progressive neurological problems.

A surgeon trained in chest (thoracic) surgery or blood vessel (vascular) surgery will perform the procedure.

Thoracic outlet syndrome surgery has risks of complications, such as injury to the brachial plexus. Also, surgery may not relieve your symptoms, and symptoms may reoccur. Your muscle strength may not return after surgery if you have serious neurological damage due to the condition.

Surgery to treat thoracic outlet syndrome, called thoracic outlet decompression, may be performed using several different approaches, including:

Transaxillary approach. In this surgery, your surgeon makes an incision in your chest to access the first rib, divide the muscles in front of the rib and remove a portion of the first rib to relieve compression.

This approach gives your surgeon easy access to the first rib without disturbing the nerves or blood vessels.

However, it allows your surgeon limited access to the area's nerves and vessels, making it difficult to see muscles and cervical ribs that may be contributing to compression behind the nerves and blood vessels.

Your surgeon then looks for signs of trauma or muscles contributing to compression near your first (uppermost) rib. Your surgeon may remove the muscles causing the compression and repair compressed blood vessels. Your first rib may be removed if necessary to relieve compression.

Infraclavicular approach. In this approach, your surgeon makes an incision under your collarbone and across your chest. This procedure may be used to treat compressed veins that require extensive repair.

In venous or arterial thoracic outlet syndrome, your surgeon may deliver medications to dissolve blood clots prior to thoracic outlet compression. Also, in some cases, your surgeon may conduct a procedure to remove a clot from the vein or artery or repair the vein or artery prior to thoracic outlet decompression.

If you have arterial thoracic outlet syndrome, your surgeon may need to replace the damaged artery with a section of an artery from another part of your body (graft) or an artificial graft. This procedure may be done at the same time as your procedure to have the first rib removed.

If you're diagnosed with thoracic outlet syndrome, your doctor or physical therapist will instruct you to do exercises at home to strengthen and support the muscles surrounding your thoracic outlet.

In general, to avoid unnecessary stress on your shoulders and muscles surrounding the thoracic outlet:

Maintain good posture

Take frequent breaks at work to move and stretch

Maintain a healthy weight

Try applying heat or massaging the painful area

Avoid carrying heavy bags over your shoulder

Avoid activities that worsen symptoms, or find ways to adapt activities so they don't cause symptoms

Create a work area that allows you to keep good posture and doesn't make symptoms worse

Symptoms associated with thoracic outlet syndrome can be caused by a number of other conditions, which makes it difficult for doctors to diagnose the condition. Many people experience thoracic outlet syndrome symptoms for years before they are diagnosed with the condition, which can cause stress and frustration.

Be sure to discuss your concerns with your doctor if your symptoms persist and a diagnosis hasn't been made.

Thoracic outlet syndrome that goes untreated for years can cause permanent neurological damage, so it's important to have your symptoms evaluated and treated early, or take steps to prevent the disorder.

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